Without any exceptions, the existing types of the Convective Inertia Force flowmeter or Coriolis Force flowmeter employ a single or a pair of conduits with two opposite extremities fixedly anchored to a supporting structure, wherein the single or pair of conduits are flexurally vibrated by a electromagnetic vibrator exerting a vibratory force on the midsection or midsections of the conduits, and the mass flow rate of media moving through the single or pair of conduits is determined as a function of an electrical parameter representing a phase angle difference in the flexural vibration of the single or pair of conduits between the two opposite halves thereof. As the individual conduits under the flexural vibration included in the existing types of the inertia force flowmeter have the two opposite ends fixedly anchored to a supporting structure, the amplitude of the flexural vibration of the individual conduit generated by the electromagnetic vibrator is limited to a very small value in the absolute sense as well as in the relative sense with respect to the length of the individual conduit, and consequently, the phase angle difference in the flexural vibration between the two opposite halves of the individual conduit is also limited to a very small value, e.g., less than five degrees. Therefore, the existing types of the inertia force flowmeter lack the sensitivity required to measure low mass flow rates of liquid media and any mass flow rate of gaseous media.
A simple mathematical analysis of the mechanical principles governing the working of the inertia force flowmeter shows that the secondary flexural vibration of the individual conduit under the flexural vibration generated by the electromagnetic vibrator, which secondary flexural vibration results from a dynamic interaction between the primary flexural vibration generated by the electromagnetic vibrator and the convective motion of media moving through the individual conduit, can have an amplitude comparable to the amplitude of the primary flexural vibration, and the phase angle difference in the resultant flexural vibration between the two opposite halves of the individual conduit can be significantly greater than five degrees, when the primary flexural vibration has a large amplitude and the structural constraint against the secondary flexural vibration is completely eliminated or limited to a low level. The present invention teaches the construction of a inertia force comprising a single or a pair of individual conduits accommodating a primary flexural vibration of a sizable amplitude and facilitating a secondary flexural vibration of a significant amplitude.